There are many CNG filling stations in Kerala. I am afraid we will not be able to provide you with this information. Hence, we suggest you to check this up with the local fuel pump dealers who would be having a ready list for the CNG stations for Kerala.
Yes you can get it installed. But we won't recommend it . Since, it will void warranty. CNG is best suited alternate fuel option instead of LPG. However, there are no CNG filling stations available in Faizabad UP. The nearest one is in Lucknow.